Electric rectifier



Feb. 19, 1935. J. e. w. MULDER I 1,991,936

EILECTRIC RECTIFIER Original Filed Nov. 22, 1928 Patented Feb. 19 1935 PATENT OFFICE ELECTRIC RECTIFIER Johannes Gijsbertus Wilhelm Mulder, Eindhoven,

Netherlands, assignor to N. V. Philips 'Gloeilampenfabrieken, Eindhoven, Netherlands Original application November 22, 1928, Serial No. 321,213. Divided and this application March 2,

1934, Serial No. 713,767.

January 13, 1928 3 Claims.

The present invention, which is a division of my copending United States application, Serial No. 321,213, filed November 22, 1928, now Patent No. 1,976,454, relates to an electric device come prising a rectifier, more particularly to a device provided with a rectifier comprising an incandescent cathode, one or more anodes, and a gaseous filling. The invention also relates to a rectifier suitable for use in such a device.

It is known that the starting voltage of discharge tubes serving for the radiation of light can be reduced by providing electrically conducting members on the outer wall of the tube and by electrically connecting the said members to an electrode.

It was to be expected that such members would also give rise to a reduction of the back ignition voltage; that is the reason why similar members are not provided in discharge tubes which do not serve for the radiation of light but for the rectification of alternating currents.

I have found that this is incorrect and that on a rectifier there can be provided electrically con-- ducting members which reduce the starting voltage without prejudicially decreasing at the same time the back ignition voltage.

For this purpose, the rectifier in an electric device according to the invention comprises one or more electrically conducting members arranged between the cathode and an anode. If these members are arranged outside the rectifier they are electrically connected to'the anode while if arranged in the interior of the rectifier, they are connected to the anode via a condenser. 'The distance from the conducting members to the anodes should preferably be smaller than that to the cathode.

The electrically conducting members may be connected across a variable condenser to an anode while if arranged in the interior of the tube, they may have the shape of a wire or a rod. The elec- .trically conducting members may consist of metal members, preferably of molybdenum, which surround the anodes and in which a diaphragm may be provided. V

The anodes are preferably arranged in arms having one or more narrowed portions provided between the cathode and the anodes while in that case the electrically conducting members may be In the Netherlands located entirely or partly between the cathode and the narrowed portions of the arms.

The invention will be more clearly understood by referring to the accompanying drawing in which: f

The Figures 1 to 3 represent different embodiments of the invention. In all these figures the wall of the discharge tube is indicated by 1, the arms of the rectifier by 2, the cathode by 3 and the anodes by 4. V

In the interior of the discharge tube shown in Figure 1 are arranged electrically conducting members 7 which are electrically connected across condensers 8 to the anodes 4.

In the mode of execution shown in Figure 2 wireshaped members 9 are located in the arms of the rectifier, said members being connected across variable condensers 10 to the anodes.

Figure3 shows a mode of realization in which the electrically conducting members are constituted by metal caps, preferably of molybdenum, composed of two parts 11 and12 and arranged in the interior of the rectifier so as to be insulated from the anodes 4. At 13 parts 11 and 12 are screwed to each other. Since the caps consist of two parts, the introduction of the diaphragm 14 is facilitated. The caps are connected via condensers 15 to the anodes.

What I claim is:

1. An electric device comprising a rectifying tube having an incandescible cathode, a num-' ber of anodes, a gaseous filling, and a cylindrical conducting member in the discharge space between each of the anodes and the cathode, and electrically connected to the anode, said members extending in the direction of the anodes and surrounding these anodes.

2. Anelectric device comprising a rectifying tube having an incandescible cathode, a number of anodes, a gaseous filling, and a cylindrical conducting member in the discharge space between each of the anodes and the cathode, and electrically connected to the anode, said members extending in the direction of the anodes and surrounding these anodes, the surrounding ends of the conducting members forming caps enclosing the anodes.

3. An electric device comprising a rectifying tube provided with arms, and having an incandescible cathode, a number of anodes located one in each of said arms of the rectifying tube, a gaseous filling, and a cylindrical conducting member in the discharge space between each of the anodes and the cathode, and electrically connected to the anode, said members extending in the direction of the anodes and surrounding these anodes, these ends of the conducting members forming caps enclosing the anodes, the said cylindrical conducting members having narrowed portions between the anodes and the cathode.

JOHANNES GIJSBERTUS WILHELM MULDER. 

